This presentation covers Basics of left ventricular geometry and moves on to elaborate surgeries for LV restoration and their basic concepts.

1. SURGERY FOR HEART
FAILURE
ABHIJIT JOSHI
NH

2. KEY CONCEPTS
• Basics of The Pump:
• THE 2 Laws - Starling & Laplace
• Ventricular Geometry and Mechanics - normal and abnormal
• Paradigms of Heart failure surgery - Vessel , Ventricle and Valve
• Evolution and different techniques of Surgical Ventricular
Restoration
• A word on Mitral Valve repair

3. TENSION AND STRESS
HOW DOES THE PUMP WORK?
• TENSION : is a linear pulling force (Newton)
• STRESS : is the force(tension) per unit cross sectional area
(Newton/metre2).
• The heart needs to develop Tension in its fibres to generate an
ejection, without adequate tension - we have heart failure.
• The aim is to have optimal tension/stress in the fibres at all times.
But what happens if this balance is tipped? The Answer lies in
Starling’s Law.

4. DESCRIBES A SINGLE MUSCLE FIBRE
STARLING’S LAW
• Starling called it “The Law of The Heart”
• “The force of contraction of the ventricular muscle fibre is
proportional to its initial resting length”
• The exact mechanism of Starling’s Law remains elusive, it closely
correlates with calcium sensitivity of the myofibres - The more the
stretch, the more the calcium sensitivity and hence more inotropy.
• Hence, Starling’s Law is a bio-chemical basis, not a physical basis.

6. • now it is easy to understand that if adequate stretch(tension) fails
to develop, there will be inadequate calcium sensitivity and
therefore inadequate contraction of each muscle fibre.
• But when does happen - Let’s now consider The Law of Laplace

7. DESCRIBES DYNAMICS OF GROUPS OF MUSCLE FIBRES
LAPLACE’S LAW
• This is a very important law, because it comes up at multiple places,
all situations involving force dynamics within a spherical object will
follow this law - whether it is the heart or it is the alveolus.
• Laplace’s law , in relation to the heart, helps us understand how the
Ventricular radius determines wall stress.
• stress =( pressure/2Xthickness ) X radius
• thus stress is directly proportional to the radius, at a particular
pressure and wall thickness, the term in the bracket is therefore the
constant of proportionality
• let’s visualise this with a simple example… (draw on the board)

9. ECCENTRIC AND CONCENTRIC HYPERTROPHY
SERIES AND PARALLEL

10. TENSION AND RADIUS
STARLING + LAPLACE
• hence, Laplace’s law gives us an idea of the stress the dilated
heart faces…
• next, let’s examine the other implication of Laplace’s law :
• tension developed is inversely proportional to the radius .
• This is the link between Starling’s and Laplace’s Laws - more the
radius, less the stretch, less the calcium sensitivity, less the force
generated by the pump.

11. GEOMETRY
AND FIBRE
ORIENTATION
OF THE PUMP

12. THE SHAPE OF THE HEART MATTERS!
WHY DISCUSS THIS?
• shape change during the cardiac cycle contributes to roughly one-
third of the thrust required for systole.
• Sallin et al showed that a ventricle with normal shape (in terms of
log to short axis ratio and sphericity index), when the myofibres
contracted by 15%, the ejection fraction was 62%.
• however altering the shape to more spherical (and less conical), at
the same 15% contraction, the EF dropped below 40%.
conversely, making it more conical, increased EF to >80%.
• this dramatic contribution is because shape influences wall
thickening .

13. SPHERICITY AND CONICITY
• a more spherical shape is better for diastole as it will offer less
resistance to ventricular filling.
• however , a more spherical shape implies increased radius, and
therefore decreased ejection force.
• hence, a more conical orientation facilitates systole.

14. MAN - THE ERECT PRIMATE, AMPHIBIAN AND GIRAFFE
SBP : 120 mm Hg SBP : 300 mm Hg
SPHERE PROLATE ELLIPSOID CONE

15. THAT’S THE SHAPE OF THE LV
PROLATE ELLIPSOID
• The normal left ventricular
shape is a prolate ellipsoid
with its long axis directed
from apex to base.
• this is a compromise between
a spherical diastole-
determined and a conical
systole determined shape.
• “prolate” = polar diameter >
equatorial diameter

16. • volume of a prolate ellipsoid
• d=diameter at the base, h=apex-base length
• this formula gives results very close to the actual measured
volumes.
v = π/6d2
h

17. INLET AND OUTLET PORTS OF THE TWO VENTRICLES
• the orientation of the LV fibres -
making it a prolate ellipsoid is
perfectly suited for systole, but
not for Passive diastole.
• the LV adapts by using this
shape configuration - it creates
a powerful suction effect during
untwisting of the fibres. this is
the dominant force during the
rapid filling phase of diastole.
• but to make use of the
untwisting force, the direction
of the inlet jet must be the same
as the direction of ejection =
bidirectional blood flow

18. • the angle between the inlet and outlet of the LV is 30 degrees,
making the flow bidirectional.
• also, this means that the mitral valve, during systole will have to
bear the full force of ejection.

19. RIGHT VENTRICLE - UNIDIRECTIONAL BLOOD FLOW
• the RV has its inlet and outlet
at an angle of 90 degrees.
• also, it has a much thinner
wall, generating much lesser
pressures - also one which less
capable of generating a strong
suction force for diastole.
• hence a large inlet port
facilitates diastole, also this
inlet port must withstand
lesser ejection force and is not
direction of ejection.

20. CRITERIA FOR OPTIMAL SHAPE
CONCLUDING REMARKS ON THE SHAPE OF THE VENTRICLE
• 1. can eject 60% of its volume in systole
• 2. reduces energy loss at pressure gradients
• 3. cross sectional dimensions in systole and diastole should be
similar to the sizes of the outlet and inlet ports respectively.
• all these will determine the stress and efficiency of the pump.

21. THE 3 LAYERS OF MYOFIBRES OF THE LV
• 1. the superficial layer - the
double helix (2layers) -
oblique fibres
• 2. the middle layer -
circumferential fibres near the
base
• 3. thin deep layer -
longitudinal fibres
• all layers have cleavage
planes in between , collagen
helps maintain the distinct
layers.

23. THE HELIX

25. • the double helix has a right handed (descending) limb which pulls
the base downwards and a left handed (ascending) limb which
pulls the apex upwards.
• the descending helix causes clockwise rotation of the base,
whereas the ascending helix causes counterclockwise rotation at
the apex. This causes twisting and shortening.
• the circumferential fibres cause compression of the cavity.
• hence ejection = compression + shortening by torsion

26. SEQUENCE OF FIBRE CONTRACTION
• systole starts with the contraction of the circumferential fibres in the pre-
ejection phase. this leads to compression of the ventricular cavity, but also
lengthens it a little.
• this lengthening acts to increase tension further so that Starling forces kick
in.
• as the circumferential fibres continue to shorten, the left ascending helix
contracts to pull up the apex towards the base and twist the apex in a
counterclockwise direction.
• soon , the right descending helix contracts.
• the right helix is much stronger and dominates over the left helix. hence
now , the base is pulled downwards and turned clockwise. during this time,
the left helix fibres lie almost horizontally, and join the circumferential fibres
in compressing the ventricle.

27. the 2 helices are oriented at an angle of 60 degrees to each other. A change in this
obliqueness, by just 5-10 degrees has a great effect on the torsion force.

29. THE APEX IS A FULCRUM
• Let’s apply the law of Laplace regionally in the ventricle, at the
apex, the region is very curved - the walls here can produce more
tension during contraction.
• thus the apex acts like a wall - a fulcrum of maximum tension
against which the remaining ventricle can eject.
• since the apex has so much curvature, it doesn’t need a thicker
wall.
• the base area therefore has the thickest walls

30. NEWER DEVICES - CORCAP
• consists of a compliant
polyester mesh jacket
• acts as an external constraint
• beneficial effect on LV
remodelling

31. MYOCOR MYOSPLINT DEVICE

32. • transventricular splint with epicardial fat pads
• adjusted to decrease LV radius
• placed without CPB through the lateral wall
• an older technique which initially got lot of interest - dynamic
cardiomyoplasty - a latissimus flap wrapped around the heart and
paced - acts as an auxillary pump.

33. ANEURYSM - LIKE MR
• gushing in of blood into an aneurysm mimics haemodynamics of MR wherein
a low impedence pathway exists for blood to flow.
• hence, development of stretch and tension in the remote fibres maybe
compromised leading to poor ejection (Starling)

34. SURGICAL
TREATMENT
TO RESIZE
& RESHAPE

35. VESSEL, VALVE AND VENTRICLE
3 MAIN SURGICAL PARADIGMS
• 1. REVASCULARISATION
• 2. VALVE SURGERY IN THE PRESENCE OF LV DYSFUNCTION
• 3. VENTRICULAR REMODELLING SURGERY

36. BATISTA PROCEDURE
• one of the first attempts at
surgical treatment for heart
failure, was done in patients
with DCM
• the rationale was to restore
Starling forces by truncating
the dilated ventricle.
• involves removing a section
of the LV free wall between
both papillary muscles, from
apex to the mitral annulus.

37. • it is now an abandoned procedure because of high recurrence
rates and high incidence of late arrythmias.
• however, initial increase in LVEF, reductions in volumes and
improved functional status in the near and mid term were
observed.
• also, this procedure assumes the disease to be homogenous in the
ventricle, however studies have suggested otherwise - the septal
and lateral walls differ in scarring and fibrosis.
• here lies the importance of newer imaging techniques to identify
diseased segments, scars and volumes accurately.

38. HIGHLIGHTS
SURGICAL VENTRICULAR RESTORATION
• the term - surgical ventricular restoration includes operative methods
that REDUCE left ventricular volume and restore its ELLIPTICAL
shape.
• initial techniques were simple aneurysm repairs, and just by resecting
the aneurysm could achieve significant improvement in LV function.
• then the techniques focussed on exclusion of infarcted segments,
asynergetic areas, but this remained the focus of these techniques
and the resultant ventricle was more spherical than desirable.
• latest techniques focus on exclusion of the infarcted segments in
conjuction with restoring the elliptical shape of the ventricle.

39. 1955
EARLIEST TECHNIQUE - LIKHOFF & BAILEY
• was done on a beating heart,
on CPB - apex is placed at the
uppermost position to avoid
air embolism, the aorta is
clamped when clot removal is
done - unclamped after full
inspection post clot removal
• involved simple aneurysm
resection and linear repair
• direct inspection shows a clear
line of demarcation between
the fibrous wall of the
aneurysm and normal muscle.

40. 1955
LIKHOFF & BAILEY
• A RIM OF SCAR TISSUE is left
behind to give a good suture
line.
• reconstruction of the LV is
done in a linear fashion from
base to apex by continuous
size 0 Mersilene sutures - full
thickness bites,with or without
teflon pledgets, reinforced by
a second lazer of horizontal
mattress sutures. interrupted
figure of 8 silk 2-0 can also be
used additionally if bleeding
points persist

41. • PITFALLS -
• septum is not addressed, only the free wall is addressed.
• the base of the aneurysm remains dilated and leads to
excessive stretch of the remote muscle.
• remnant scar and necrosed endocardium can be a focus of
arrythmias

42. JATENE’S TECHNIQUE
• septal bulge is plicated by
horizontal sutures
• then a purse string around
the mouth of the aneurysm -
addresses the base of the
aneurysm

43. STONEY’S REPAIR
ADDRESSES THE SEPTUM ALSO

44. VIDEO
MODIFIED LINEAR REPAIR - LYNDA MICKLEBOROUGH
• done on a beating heart
• relatively simple technique, reproducible with good results
• midline sternotomy, aortic and bicaval cannulation, temperature is not allowed to drop
below 35, as that might cause fibrillation
• go on CPB, at this stage an area of dimpling maybe visible - making the infarct area clear.
• but this technique relies on examining with a beating heart and not on the line of
demarcation.
• the aneurysm is then incised, reduced LV pressures keep the aortic valve shut.
• stay sutures are applied, clots removed in one piece as far as possible.
• the edges of the beating heart ARE PALPATED TO ASSESS CONTRACTILITY, areas that
do not contract are resected

45. • Before final trimming, the size and shape of the remaining left ventricular cavity
are assessed in the beating heart. It is important for this evaluation that the
surgeon should have an understanding of normal ventricular size and shape, as
well as of the normal spatial relationships that exist between the papillary
muscle insertions and the septum, which must not be distorted in the closure.
• modified linear closure is done from both ends of the ventriculotomy, Bites of
the tissue are approximately 1 cm deep. To plicate the length of the incision
the sutures are placed further apart on the tissue edge than on the felt strips.
As the sutures are tied, the incision is ‘‘gathered’’ which helps restore the shape
of the ventricle towards its normal conical shape

46. • PATCH SEPTOPLASTY is done to address the septal bulge whenever present
Mattress sutures are placed incorporating the anterior edge of the septal patch into
the modified linear closure.
see video

47. • arrythmias are addressed by :
• endocardial scar excision
• cryoablation of deep septal foci (-60 degrees celsius for 2
mins each)

48. DOR’S ENDOVENTRICULAR CIRCULAR PATCH PLASTY (EVCPP)
• done on an arrested heart
• RSPV vent used to decompress LV
completely
• ventriculotomy done 2-3cm lateral to
the LAD
• extent of scarring visually
determined
• a plane of dissection is developed
between the endocardial scar
covering the distal septum and
underlying septal myocardium
• in most cases the septal scar is
resected out, in some instances when
the scar is strong enough and the
flap large enough - it can be used to
close the ventriculotomy (draw)

49. • An endoventricular circular suture (Fontan maneuver) is placed 1 cm
distal to the border of healthy muscle in order to prevent its inclusion
and allows recreation of the normal shape of LV using continuous 2-0
monofilament polypropylene suture. Following this, a balloon is
placed in LV cavity and inflated to the theoretical diastolic volume of
50–70 ml/m2, and the circular suture is tightened and tied up.

50. • after the continuous suture
layer, a layer of interrupted
sutures is taken on which the
patch will be fixed, akin to a
valve replacement.
• the ventriculotomy is then
closed
• P.S. the figure shows
continuous sutures, these too
can be used

51. IT ENDS UP TOO SPHERICAL
PITFALL OF DOR’S TECHNIQUE - POCAR’S STUDY
• The original Dor’s technique resulted in a heart which is too spherical.
• subsequent modifications aim to change this:
• Menicanti modification of Dor’s Technique, a similar technique is used at
San Donato
• Cooley’s technique, a similar technique is used at San Donato
• PV Rao’s technique - linear(rectangular) patch plasty

52. MENICANTI MODIFICATION
• the inferior fibrotic wall is plicated
• the fontan stitch angle is changed - carried deep toward the septum ,
upwards toward the aortic outflow tract on an oblique plane - to reconstruct
an elliptical shape rather than a spherical one
• the new apex is more conical
The plane of the closure should not be parallel to the mitral valve . If the closure plane is
parallel to the mitral valve, the result is a spherical chamber

53. note the plicated inferior wall and the oblique fontan stitch

55. COOLEY’S TECHNIQUE - ANEURYSMORRHAPHY
• does not plicate the inferior
fibrotic wall, excludes it - better
for arrythmias prevention. PATCH
SEWN ON THE SEPTUM AND
THE DEFECT IS DRAWN IN.
• uses an elliptical patch to create
conicity , similar to menicanti
• direct closure of the
ventriculotomy - no felt strips -
reduces infection rate, also
beyond the patch , the ventricle
walls are not subjected to higher
pressures

56. LINEAR ENDOVENTRICULAR PATCH PLASTY
PV RAO’S TECHNIQUE
• No use of the Fontan Stitch - this
plication maneuver at the
transistional zone increases
sphericity
• No use of LV volume measuring
devices - fallacious in the arrested
heart
• RECTANGULAR PATCH - a more
elliptical configuration is achieved
herein.
• Teflon strips used to stabilise
ventriculotomy
• exclusion of infarcted zone from
apex to base inclusive of the
septum and free wall of LV

59. GEOMETRY !
WHY IS A RECTANGULAR PATCH BETTER
• consider a mathematical model,
wherein the aneurysm/patch is
considered to be part of a sphere.
• the borders of the aneurysm/
patch subtend an angle at the
centre of the sphere.
• THIS ANGLE WAS ALWAYS
LESSER FOR RECTANGULAR
ANEYRYSMS.
• THUS MORE CONTRACTILE
MUSCLE IS PRESENT ACTIVELY
CONTRIBUTING TO EJECTION
IN A RECTANGULAR PATCH

62. FURTHER READING
• Results of the surgeries
• STICH trial
• MV repair and annuloplasty along with SVR

63. THANK YOU
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